Question

Imagine that time travel really is possible, and you get to meet Albert Einstein. As you talk with him, you summarize what you think you understand about his theory of relativity as follows: “Space, being represented by a three-dimensional sphere, can be curved inward under an object with mass.” How would you expect Einstein to react to this summarization?%0D%0A%0D%0A(1 point)%0D%0AResponses%0D%0A%0D%0AHe would correct you and explain that space, rather than being represented by a three-dimensional sphere, is actually represented by a flat grid.%0D%0A%0D%0AHe would correct you and explain that space, rather than being represented by a three-dimensional sphere, is actually represented by a flat grid.%0D%0A%0D%0AHe would agree with most of your statement but correct you that space can only be curved by objects with a mass greater than 2 AU.%0D%0A%0D%0AHe would agree with most of your statement but correct you that space can only be curved by objects with a mass greater than 2 AU.%0D%0A%0D%0AHe would agree with everything you said, appreci

Answer 1

He would correct you — space is not literally a three‑dimensional sphere or just a “dip” in a flat grid. More precisely, Einstein would say that spacetime is a four‑dimensional manifold whose geometry (the metric) is curved by energy and momentum (the stress–energy tensor). The common “rubber sheet” picture is only an analogy/embedding diagram; it can mislead (it uses an extra spatial dimension to visualize curvature and suggests an “inward” direction).